School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
Division of Endocrinology and Metabolism, Department of Internal Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan.
Medicine (Baltimore). 2022 Jun 24;101(25):e29337. doi: 10.1097/MD.0000000000029337.
Hypoglycemia is an emergent condition with many causes, including underlying diabetes mellitus either with the use of insulin or oral anti-diabetic medications for glucose control, and organ (heart, hepatic, or renal) failure. Insulin autoimmune syndrome (IAS) can also cause hypoglycemia, however it is relatively difficult to diagnose as it is rare clinically. Although uncommon, IAS can be life threatening in patients with persistent hypoglycemia.
We report the case of a 27-year-old female with underlying Graves' disease who was treated with methimazole (MTZ). After 6 weeks of treatment, she developed hypoglycemia symptoms accompanied by dizziness and cold sweating. We excluded underlying diabetes mellitus, the use of insulin or oral anti-diabetic medications, and organ failure.
Laboratory data showed elevated insulin and C-peptide levels. Therefore, insulinoma and IAS were suspected. Abdominal computed tomography and magnetic resonance imaging ruled out insulinoma, and MTZ-induced IAS was finally diagnosed.
The hypoglycemia symptoms resolved after MTZ was switched to propylthiouracil, confirming the diagnosis of IAS.
This case emphasizes the significance of life-threatening MTZ-induced IAS. IAS should be suspected in patients who develop spontaneous hypoglycemia, especially in those with underlying Graves' disease receiving MTZ who present with hyperinsulinism.
低血糖是一种紧急情况，有许多原因，包括基础糖尿病，无论是使用胰岛素还是口服抗糖尿病药物来控制血糖，以及器官（心脏、肝脏或肾脏）衰竭。胰岛素自身免疫综合征（IAS）也会导致低血糖，但由于临床上较为罕见，因此较难诊断。尽管不常见，但持续低血糖的患者可能会因 IAS 而有生命危险。
我们报告了一例 27 岁女性患有基础 Graves 病，接受甲巯咪唑（MTZ）治疗。治疗 6 周后，她出现低血糖症状，伴有头晕和冷汗。我们排除了基础糖尿病、胰岛素或口服抗糖尿病药物的使用以及器官衰竭。
实验室数据显示胰岛素和 C 肽水平升高。因此，怀疑为胰岛素瘤和 IAS。腹部计算机断层扫描和磁共振成像排除了胰岛素瘤，最终诊断为 MTZ 诱导的 IAS。
将 MTZ 换用丙基硫氧嘧啶后，低血糖症状缓解，确诊为 IAS。
本病例强调了致命性 MTZ 诱导的 IAS 的重要性。对于出现自发性低血糖的患者，尤其是正在接受 MTZ 治疗的基础 Graves 病患者，出现高胰岛素血症时，应怀疑 IAS。
